1. Field of the Invention
This invention concerns the production of fluoralkyl substituted olefins, fluorinated ketones and fluorinated benzenes by the catalyzed reaction of fluoroalkylsilanes with selected fluorinated olefins, acyl fluorides, and fluorinated aromatic compounds, respectively. The products are useful as chemical intermediates, solvents and as monomers for polymerization.
2. Background Art
G. K. Prakash, et al., J. Am. Chem. Soc., Vol. 111, 393-395 (1989) describe the reaction of the fluoride ion catalyzed reaction of trifluoromethyltrimethylsilane with ketones and aldehydes to give the corresponding .alpha.-trifluoromethyl substituted alcohol and trimethylfluorosilane. In a typical reaction, cyclohexanone was reacted with trifluoromethyltrimethylsilane in tetrahydrofuran in the presence of tetrabutylammonium fluoride at 0.degree. C. After 1 hour, the solution was mixed with 0.5 N HCl to hydrolyze the intermediate silyl ether, and then the product was isolated by distillation. In this case, a 77% yield of 1-trifluoromethylcyclohexanol is reported.
J. D. Citron, J. Organometal. Chem., Vol. 30, 21-26 (1971) reports the uncatalyzed reaction of silicon compounds containing a variety of functional groups with acyl fluorides. Fluoroalkylsilanes are not mentioned as a reactant.
G. P. Stahly, U.S. Pat. No. 4,804,774, describes the reaction of quinones with perfluoroalkylsilanes in the presence of certain phosphorous containing catalysts to form compounds wherein the silicon atom is attached to one of the oxygen atoms of the quinone and the perfluoroalkyl group is attached to the carbon atom to which said oxygen is attached. In other words, the perfluoroalkylsilane adds across the carbonyl double bond. In Comparative Examples A and B, this reference describes the reaction of benzoquinone with triethyltrifluoromethylsilane, catalyzed by sodium fluoride and calcium fluoride respectively. It is reported that no reaction takes place.
U.S. Pat. No. 4,634,787 to Wang claims the fluoride catalyzed reactions of trihalomethylsilanes with aldehydes, ketones and quinones. The products are (2,2,2-trihalo-1,1-dihydrocarbylethoxy)trihydrocarbylsilanes. Preferred halo groups are chloro and bromo. Fluoro groups are neither exemplified nor specifically mentioned.
G. P. Stahly and D. R. Bell, J. Org. Chem., Vol. 54, 2873-2877 (1989) report the catalyzed reactions of quinones with trifluoromethylsilyl compounds, wherein the silyl compound adds across the carbonyl of the quinone. Thus, the reaction of 1,4-benzoquinone with trifluoromethyltrimethylsilane yields 4-trifluoromethyl-4-trimethylsiloxy-2,5-cyclohexadieneone. Some of the catalysts are cesium fluoride, potassium bifluoride, tetrabutyl ammonium bifluoride, potassium cyanide and potassium carbonate.